Technical Field
The invention relates to the field of open ocean structures and fish farming, and in particular, to automated positioning and submersible open ocean structures suitable for growing and harvesting fish and systems employing such structures for open ocean fish farming.
Background Art
Prior attempts have been made to develop aquaculture systems for growing and harvesting fish by mooring or tethering cage structures to shore piers or by anchoring them to the sea floor. Floating aquaculture apparatus moored by anchors and submerged in natural bodies of water, and artificial island reef platforms for raising quantities of pelagic fish with design features that include a subsurface framework, cabling network, multiple cages and stable anchoring systems, are known in the art.
One such structure for near-shore-deployed ocean fish farming comprises a sea cage having a central stem with an air chamber for controlling buoyancy for surfacing or submerging. The bottom of the central stem is tethered to an anchor (or anchors) or grid mooring system on the sea floor. The outer periphery of the cage has mesh netting forming the outer boundaries for the cage. Even when deployed in ocean waters, wastes from the growing fish can become concentrated in the cage volume and the mesh netting may become contaminated and not able to be cleaned efficiently at sea.